Double walled container



w. J. PODBIELNIAK DOUBLE WALLED CONTAINER Filed June l2 Nov'. 21, 1933.

Patented Nov. 21, 1933 masses DOUBLE WALLED coNrAmEn 'walter J.romanian, Trim, om.- t appucaunnrm iz. 1931. serial ism-543,939 4cm.(ciauz-zza) The present invention relates to improvements 4 in-doublewalled containers, the inner and outer walls of which may be exposed todifferent temperatures, and more particularly to elongated,

5 evacuated containers or jackets employed as insulating jackets forfractional distillation columns or as the columns themselves. Theinvention will be more fully understood from the following descriptionthereof, illustrated by the accompanying drawing, in which:

Figure 1 is a sectional view, partly broken away, through a distillationapparatus provided with a vacuum jacketed container embodying thepresent invention; and

Fig. .2 is a detail sectional view upon an enlarged scale, partiallybroken away, of portions of the inner wall of the evacuated container asseen at the left side of Fig. 1.

Referring morevparticularly tothe drawing, which shows a distillationapparatus of the type .more fully described in my prior applications475,584 and 475,585, both filed August 15, 1930,

the numeral Sedesignates a distillation column, the lower end of whichis enlargedy to form a distilling bulb 6, provided at its lower end witha constricted elongated portion 7 to which heat ,may be applied, forexample,by the electrical heating element 8.

Surrounding the distilling tube 5 for substantially its entire length,there is an evacuated, double walled container or jacket 9,'constructedin accordance with the present invention as more fully hereinafterdescribed, and serving as an insulating jacket for the distilling tube.At its lower end, the jacket member 9 is enlarged, as at 9', to surroundthe distiuing bulb s. at the lower' end of the jacket 9,' the distillingtube 5 may be held in position by a suitable cork or washer 10 and also,if desired, by' packing material 11 sur- 40 rounding the lower end ofthe.distilling bulb 6.

At the upper end of the double walled jacket 9,

it is'enlarged, as at 9b, and in the enlarged space l thus providedaround the upper end of-thedistillation column 5, a container 12 ofannular cross section-is provided, surrounding the column 5. In-

ing into and out of the chamber I2 for the supply and removal of acoolingI medium'. and suitable packing,'such as at 15, may be suppliedwithin the annular cooling chamber 12 for distribution of the coolingmedium when a vaporizable material, such as liquid air, is employed forthe purpose. The column 5'may be supported in relative position in theupper portionr9b of the jacket 55, byxneans of a suitable perforatedcork'or washer 16 and packing may beprovided within the enlarged upperportion 9b of the jacket surrounding kthe column 5 and the chamber 12,as shown at 17.

The double walled jacket 9, with its enlarged` end portions 9a and 9bhas hitherto been con- 00 structed of glass, preferably a low-expansion,

Aheat resistant glassof the borosilicate or other readily availabletype, such as that commercially known as Pyrex, and provided with silvermirrors on one Aor both of the inner Walls, thus forming, on evacuation,an eilicient insulating jacket. In use, however, the innei` wall 18 ofthe jacket 9 is subjected to a wide range\of tempera-l ture variations,particularly the long, central straight portion thereof, while the outerwall is subjected to a relatively minor range of temperature variations,ordinarily but little above or be' flowthe -normal surroundingatmospheric temperatures. The variations in temperatures to which theinner wall of such an insulated con- "f5 tainer are subjected maybe evengreater when the inner wall is itself employed as the distillationcolumn.. The temperature variations may be from temperatures of -400 F.l(or lower) to -|-300 to 400 F. V(or higher) in the analytical dis- 80tillation of natural gas hydrocarbons and natural gas gasoline, andtemperatures very considerably higher, say to 500 to 600 F. may bereached in the distillation of kerosene, napthas, or other liquidpetroleum products.

As a result of the greatl differences in the temperature variations towhich the inner and outer walls of the double walled jacket 9 yaresubjected, as hitherto constructed, there have been great dinerences invthe expansion and contraction of the inner wall 18, and'particularlythe elongated central portion thereof, with respect to the remainingportions of the jacket orcontainer, 9.

-To a certain extent these variations may be taken care of by a slightbowing of the inner wall 1B, the 95 curvature of the wall decreasing asthe temperature of the inner wall drops relative to the outer wall andincreasing as it rises. However, and particularly when vey greattemperature varia- V ,tionsmay be present, such variations in curvaturelet and outlet pipes 13 and 14 are provided, leadof any bow or arch thatmaybe provided in the inner wall 18 may not be sufficient to avoidimpairment or'breakage of the apparatus.

In accordance-with the present invention, the

inner wall 18 of thedouble-walled container or 105 l jacket 9 isformedof fused quartz, the,I transf parent fused quartz' being preferablyemployed. While the entire inner wall of the jacket 9 may beconstructed. of quartz, itis preferred to use quartz in its constructiononly'from about the 11 point of the upper enlargement of the-container 9at 9b, say the 'point 18' to the lower end ofthe inner wall, as at 18D,this being the portion of the apparatus subjected to the greatestvariations in temperature. At these points, the inner quartz tube isjoined to the low-expansion glass of which the remainder of thecontainer is constructed by any suitable sealing means. for example, bywhat is known in the glass blowing art` as a graded joint built up byfusion oi. particles of quartz and the glass employed with graduallyincreasing proportions of glass. The points where these graded jointsare provided are indicated in the drawing 'at 18n and 18h.

It is readily'apparent that the inner, quartz tube portion of thecontainer or jacket 9 made in accordance with the present invention maybe :slightly bowed,'iI desired, and that the walls of the jacket orcontainer 9 may be provided with mirrors internally, if. desired. Byconstructing the inner wall, which is exposed to the widest range oi?vtemperature variations, of quartz, the

variations in its length due to expansionA and contraction are markedlyreduced and more nearly equalized with\those taking place in the outerwall of the container or jacket. It is readily apparent that if thecontainer or jacket is to be used under circumstances wherein they outerwall of the container' or jacket are subjected to the greatestvariations in temperature, the outer wall will be formed of quartz,joined or sealed to the low expansion glass' or-other glass forming theremainder of the device. Furthermore, itisreadilyapparentthatinmanycaseaitwillnot be necessary-to use thevlow-expansion type of glassware in constructing those portions' of thejacket'not exposed to wide temperature variations. I claim: A 1. Anelongated, double walled, insulating container adapted to have a wallportion thereof 3. In, distillation apparatus, adouble walled,

evacuated container' of elongated, cylindrical form, the inner wall of-said container being adapted to be subjected to marked variations intemperature, said inner wall being formed of fused quartz and theremainder of the container being formed of glass joined and sealed `tosaid quartz inner Wall.

4. In distillation apparatus, an elongated distillation column.forcontaining the material to be distilled, a double-walled, evacuatedcontainer surrounding said column, the inner wall of said containeradjacent the column, being formed of fused quartz and the remainder ofthe container being formed of low-expansion glassjoined and sealed tosaid quartz inner wall. e

. 'f vWALTER J.

